Electrical Studies of Gel Polymer Electrolyte based on PAN for Electrochemical Cell Applications

The free standing and dimensionally stable Gel Polymer electrolyte films of PAN: KI of varying compositions using Ethylene carbonate (EC) as a plasticizer and dimethyl formamide (DMF) as solvent are prepared by adopting ‘solution casting technique’ and these films are probed for their conductivities. The miscibility and the chemical rapport between PAN and KI are investigated using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and Differential Scanning Calorimetry (DSC) methods. The conductivity is increased with the increase of KI concentration as well as temperature. The maximum conductivity at 30 oC is found to be 2.089 X 10-5 Scm-1 for PAN:KI (70:30) wt.% which is nine orders greater than that of pure PAN (<10-14 S cm-1). The conductivity-temperature dependence of these polymer electrolyte films obeys Arrhenius behaviour with activation energy ranging from 0.358 eV to 0.478 eV. The conducting carriers of charge transport in these polymer electrolyte films are identified by Wagner's polarization technique and it is found that the charge transport is predominantly due to ions. The highest conducting sample is used to fabricate the battery with configuration K/ PAN+KI /I2+C+electrolyte and good discharge characteristics of battery are observed.